1. To prepare dipping sauce, combine first 4 ingredients in a blender; process until smooth. Stir in 1/4 teaspoon salt; cover and chill 30 minutes.
2. To prepare skewers, combine pineapple juice, olive oil, rind, garlic, 1/4 teaspoon salt, and 1/8 teaspoon red pepper in a large bowl. Add shrimp; toss to coat. Let stand 10 minutes.
3. Thread 2 shrimp and 2 pineapple cubes alternately onto each of 10 (6-inch) skewers. Brush skewers with pineapple juice mixture. Heat a heavy grill pan over medium-high heat. Coat pan with cooking spray. Add skewers to pan; cook 4 minutes on each side or until shrimp are done. Serve with dipping sauce.